An installation of the abovementioned type is described in the two earlier European patent applications 04405 704.0 and 04405 751.1, filed on Nov. 16, 2004 and Dec. 3, 2004, respectively. In the case of this installation which is integrated in an outgoing generator line, a current conductor carrying generator current is kept at a desirably low operating temperature with the aid of cooling elements. Each of the cooling elements has an evaporator, which is arranged on the current conductor with good thermal contact and contains a liquid working medium, as well as a condenser, which is arranged on an encapsulation acting as an outer conductor in such a way that it is electrically insulated from the evaporator or the current conductor, depending on the embodiment of the cooling element, or is located in the interior of the encapsulation and then needs to be cooled by means of convection with the aid of a gas flow.
An unencapsulated installation of the abovementioned type is described in the earlier European application 04405786.7, filed on Dec. 20, 2004. In the case of this installation, a current conductor, which is formed by the two contact pieces and the electrical terminals of a vacuum interrupter, is kept at low operating temperatures with the aid of at least one cooling element, which likewise functions on the basis of the condensation principle. The cooling element and further cooling elements which may be provided are subjected to the direct influence of the ambient air.
Furthermore EP 0 395 314 A1 has disclosed a superconductor system for energy distribution, in which the current is transmitted from a power supply unit to subsystems by means of superconductors. The current transmission in the superconductor system therefore takes place without any losses, i.e. without any Joulean heat being produced, which corresponds to the definition of a superconductor (sudden loss of electrical resistance below a critical temperature). EP 0 395 314 A1 has merely disclosed the fact that heat which is transmitted from the heat reservoir of the surrounding environment to the cold reservoir of the superconductor is dissipated by a cryogenic liquid. The superconductor also has a multiple-shell sheathing for thermal insulation, which is intended to suppress a transmission of heat over the entire length of the superconductor. Furthermore, the superconductor system has a complex pipeline circuit for conducting the cryogenic liquid, to which a condensation unit is coupled which contains a condenser.